Location system

ABSTRACT

A location system comprises a communication terminal for transmitting a location request specifying a target mobile terminal and a type of location information, and a location network. In response to the location request, the location network produces current location information of the target mobile terminal if the type of location information of the received request specifies current location information and transmits the current location information to the communication terminal and stores the last known location information in a memory as last known location information of the target mobile terminal. If the type of location information specifies last known location information, stored last known location information of the target mobile terminal is copied from the memory and transmitted to the communication terminal if the location request is verified by a privacy check and if the stored information is reusable.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates generally to location systems forproviding information services to clients as to the location of mobileuser equipment (UE) terminals according to the 3GPP (Third GenerationPartnership Program) Technical Specification 23.271 v. 5.3.0,“Functional stage 2 description of LCS”, pages 33-62, June 2002. Morespecifically, the present invention is concerned with the reuse of lastknown location information.

2. Description of the Related Art

The location information of a mobile UE terminal is usually sensitive tothe privacy of the mobile user and often crucial when the user is in acritical situation. To protect mobile users from illegal access to theirprivate location information, the mobile communications network isprovided with a sophisticated privacy protection mechanism which imposesvarious restrictions on location requests according to privacy profiles(time and place) specified by the mobile users. The privacy protectionmechanism provides two types of verification on a location requestaccording to decision capability that varies with a point in the networkwhere the location request is being served. The first type ofverification is performed on a client terminal when the network receivesa location request from this terminal, known as client check. The secondtype of verification is a permission granted to the location requestafter location information of a UE terminal has been obtained if theplace and time interval specified by the privacy profile of the UEterminal user are satisfied, known as privacy check.

Mobile network providers, on the other hand, are required to providelocation service in addition to their basic mobile communicationsservice. Specifically, the location service involves several networknodes exchanging special messages with one another for the positioncalculation of a target UE and exchanging messages with a target UEterminal over wireless link.

The 3GPP location information system, as specified in the 3GPP standard,is basically made up of client terminal, GMLC (Gateway Mobile LocationCenter), SGSN/MSC (Serving General packet radio service SupportNode/Mobile Services switching Center), local wireless network known asRAN (Radio Access Network) and UE (User Equipment) terminal connected tothe RAN via wireless link. HLR/HSS (Home Location Register/HomeSubscriber Server) is connected to the GMLC as a database for holdingthe identity of the RAN to which UE terminals are connected. Registeredclient terminals are given exclusive right to access UE terminals.

The 3GPP standard provides two modes of operation for requestinglocation information, i.e., the mobile terminated location request(MT-LR) and the mobile originated location request (MO-LR). In the MT-LRmode, the client terminal can either request the current location of atarget UE or the current or last known location of this terminal. Thelast known location information is used as a location report instead ofthe current location information when the network has failed in locatingthe target UE for some reason if the last known location information isusable.

More specifically, when the network receives a location request for atarget UE, the SGSN/MSC responsible for the management of the target UEis also responsible for the privacy protection of the UE terminal.According to the privacy protection of the MT-LR mode as specified bythe 3GPP standard, UE mobile users register their privacy profile (e.g.,the identifiers of those clients allowed to request their location) inthe SGSN/MSC of their home network. In response to a location request,the SGSN/MSC performs a privacy check by verifying it against theregistered privacy profile of the target UE and determines whether ornot the location request is granted. If the privacy profile of a UEterminal further specifies that a notification/verification request besent to the UE terminal, the UE terminal is given a notification that itis being targeted or verifies the location request and returns averification result to the client terminal. When the location request isacceptable, the SGSN/MSC proceeds with a location estimation process incollaboration with the associated RAN to determine the current locationof the target UE. If the SGSN/MSC fails to acquire current locationinformation of a target UE, a copy of the stored last known locationinformation of the target UE is transmitted to the client terminal ifthis information is currently still usable, or significant.

In the MO-LR mode, the mobile UE terminal exclusively requests its owncurrent location from the network. In this mode, a failure in locationmeasurement will result in the transmission of an error report to therequesting mobile UE terminal. Last known location information is notreused at all for transmission instead of the error report.

However, a number of shortcomings exist in the prior art locationsystem.

First, the flow of traffic through the location network and the amountof location measurement calculations increase in proportion to locationrequests from client and mobile terminals. Further, part of the locationnetwork is shared in common by a mobile communication network.Therefore, when the location network experiences heavy traffic loads, itis likely that mobile communication traffic is adversely affected, whichcould lead to an extra burden on mobile network providers.

Second, in the MT-LR mode of operation, privacy check is performed bythe SGSN/MSC. If reusable last known location information of a UEterminal is available in the GMLC, for example, the SGSN/MSC wouldperform privacy check for the UE terminal. However, no mechanism isprovided for the GMLC to request the SGSN/MSC to perform privacy check.As a result, privacy protection of last known location information isonly ensured when this private information is maintained in the GMLC.

Third, the reusability of last known location information dependsexclusively on whether or not an SGSN/MSC is holding the last knownlocation information, and the criteria of usability depends on specificdetails of an SGSN/MSC which may differ among different SGSN/MSCs.Therefore, it is likely that requesting client terminals may receiveworthless last known location information.

SUMMARY OF THE INVENTION

It is therefore an object of the present invention to provide a locationsystem that reduces location traffic loads and measurement calculationloads and concomitant elimination of an extra network cost.

It is a further object of the present invention to provide a locationsystem capable of utilizing last known location information of a mobileterminal for both MT-LR (mobile terminated location request) and MO-LR(mobile originated location request) modes of operation, regardless ofwhether an SGSN/MSC has failed in obtaining current location informationof a target mobile UE (user equipment) terminal.

It is a still further object of the present invention to provide alocation system capable of providing privacy protection of target UEterminals when their last known location information are reused.

It is a still further object of the present invention to provide alocation system capable of establishing reusability criteria for lastknown location information according to requests from client terminalsas well as from UE terminals indicating an age parameter of their lastknown location information.

According to a first aspect of the present invention, there is provideda location system for locating a plurality of mobile terminals. Thesystem comprises a communication terminal for transmitting a locationrequest specifying a target mobile terminal and a type of locationinformation, and a location network. The location network is responsiveto the location request from the communication terminal for producingcurrent location information of the target mobile terminal if the typeof location information of the received request specifies currentlocation information and transmitting the current location informationto the communication terminal and storing the last known locationinformation in a memory as last known location information of the targetmobile terminal, and copying stored last known location information ofthe target mobile terminal from the memory if the type of locationinformation specifies last known location information and transmittingthe copied information to the communication terminal.

The network performs a reusability test on the stored last knownlocation information and transmits the last known location informationif the reusability test indicates a favorable result and transmits thecurrent location information if the reusability test indicates anunfavorable result.

According to a second aspect, the present invention provides a locationmethod comprising the steps of transmitting a location request from acommunication terminal, the request specifying a target mobile terminaland a type of location information, receiving the location request at alocation network, producing current location information of the targetmobile terminal and transmitting the current location information fromthe location network to the communication terminal if the type oflocation information of the received request specifies current locationinformation, storing the current location information in a memory aslast known location information of the target mobile terminal, andcopying the stored last known location information of the target mobileterminal from the memory if the type of location information specifieslast known location information and transmitting the copied informationfrom the location network to the communication terminal.

According to a third aspect, the present invention provides a method ofoperating a gateway with a location network. The method comprises thesteps of receiving a location request from a communication terminal,said request specifying a target mobile terminal and a type of locationinformation, acquiring current location information of the target mobileterminal from said location network and transmitting the currentlocation information to said communication terminal if the type oflocation information of the received request specifies current locationinformation, storing the current location information in a memory aslast known location information of the target mobile terminal, andtransmitting a copy of the stored last known location information of thetarget mobile terminal to said communication terminal if said type oflocation information specifies last known location information.

According to a fourth aspect, the present invention provides acommunication terminal which comprises a transmit means for transmittinga location request to a location system in which last known locationinformation of mobile terminals are stored, the location requestspecifying a target mobile terminal and a type of last known locationinformation, and receive means for receiving from the location system acopy of current location information of the target mobile terminal ifthe type specifies current location information or a copy of last knownlocation information of the target mobile terminal if the type specifieslast known location information.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be described in detail further with referenceto the following drawings, in which:

FIG. 1 is a block diagram of a location system of the present invention;

FIGS. 2A and 2B are block diagrams useful for describing a first networkconfiguration of the present invention;

FIG. 3 is a block diagram useful for describing a second networkconfiguration of the present invention;

FIG. 4 is a block diagram useful for describing a third networkconfiguration of the present invention;

FIG. 5 is a block diagram useful for describing a fourth networkconfiguration of the present invention;

FIG. 6 is a block diagram useful for describing a fifth networkconfiguration of the present invention;

FIGS. 7A and 7B are block diagrams useful for describing a sixth networkconfiguration of the present invention;

FIGS. 8A and 8B are block diagrams useful for describing a seventhnetwork configuration of the present invention;

FIGS. 9A and 9B are block diagrams useful for describing an eighthnetwork configuration of the present invention;

FIGS. 10A and 10B are block diagrams useful for describing a ninthnetwork configuration of the present invention;

FIGS. 11A and 11B are block diagrams useful for describing a tenthnetwork configuration of the present invention;

FIGS. 12A to 12E are flowcharts of the operation of a local GMLC whichmaintains the privacy information of its home UE terminals, and FIG. 12Fis a flowchart of a local GMLC which does not maintain the privacyinformation of its home UE terminals;

FIG. 13 is a flowchart of the operation of a SGSN/MSC of the presentinvention;

FIG. 14 is a flowchart of the operation of a mobile terminal of thepresent invention;

FIGS. 15A, 15B and 15C are sequence diagrams associated with the firstnetwork mode of operation of the present invention;

FIG. 16 is a sequence diagram associated with the second network mode ofoperation;

FIG. 17 is a sequence diagram associated with the third network mode ofoperation;

FIG. 18 is a sequence diagram associated with the fourth network mode ofoperation;

FIG. 19 is a sequence diagram associated with the fifth network mode ofthe present invention;

FIG. 20 is a sequence diagram associated with the sixth network mode ofthe present invention;

FIG. 21 is a sequence diagram associated with the seventh network modeof the present invention;

FIG. 22 is a sequence diagram associated with the eighth network mode ofthe present invention;

FIG. 23 is a sequence diagram associated with the ninth network mode ofthe present invention; and

FIG. 24 is a sequence diagram associated with the tenth network mode ofthe present invention.

GENERAL DESCRIPTION

Referring now to FIG. 1, there is shown a location system of a mobilemulti-network in which the present invention is incorporated. Thelocation system is comprised of a plurality of client terminals 101,111, 121 connected via landline links to a location network and a mobileUE terminal 105 wirelessly connected the location network.

The location network is formed by a plurality of GMLCs (Gateway MobileLocation Centers) 102, 112, 122 to which client terminals 101, 111, 121are respectively connected to send their location requests to andreceive location reports from the associated GMLCs. GMLCs 102, 112, 122are connected to SGSN/MSCs (Serving General packet radio service SupportNode/Mobile service Switching Centers) 103, 113 and 123, respectively,and mutually connected to one another. SGSN/MSCs 103, 113, 123 arerespectively connected to RANs (Radio Access Networks) 104, 114, 124.Further associated with the GMLCs 102, 112, 122 are HLR/HSSs (HomeLocation Register/Home Subscriber Server) 106, 116 and 125. Privacyprofile registers (PPR) 107, 117, 127 are also connected to the GMLCs102, 112, 122, respectively.

The network nodes which are directly connected to each other, such asGMLC, HLR/HSS, SGSN/MSC, RAN, PPR, form a group known as a home networkfor mobile UE (user equipment) terminals. For example, a UE terminal 105is connected as a home UE terminal via a wireless link to the RAN 104.

As shown in FIG. 1, the client terminal transmits a location requestmessage 150 having a number of fields containing a message type, asource address (client's identifier), a destination address (phonenumber of target mobile UE terminal), a location information type and areusability criteria. The location information type field specifies atype of location information (C=current, L=last known, C/L=current orlast known, or L/C=last known or current). The “current or last known”type indicates that the current location information is given priorityover the last known location information if both information areavailable, and the “last known or current” type of location informationindicates that the last known location information is given priorityover the current location information if both information are available.Current location information may be a default setting. If the requestinguser desires a previous location of a target UE terminal, theinformation-type field of the message is set equal to L. If therequesting user desires a previous location of a target UE terminal, butallows current location information if the previous location is notavailable nor reusable, the message contains an information-type fieldset equal to L/C. The information-type field of the message may be setequal to C/L if the user allows last known location information ifcurrent location information is not available. The reusability criteriafield of the location request message specifies the accuracy of lastknown location information (allowable distance error) and the allowableage of last known information. The reusability criteria will be used bythe location network to make a decision as to whether stored last knownlocation information of a UE terminal can be reused.

Each mobile terminal is also capable of transmitting a location requestwhich specifies its own mobile terminal and contains a type of locationinformation.

The location network stores last known location information of themobile terminals. The location network is responsive to a locationrequest from the communication terminal, either from client terminal ormobile terminal, for producing current location information of a targetmobile terminal specified by the request and transmitting it to thecommunication terminal if the type of location information of thereceived request is current location information, and transmitting acopy of the stored last known location information of the target mobileterminal to the communication terminal if the type of locationinformation is last known location information.

The location network is responsive to a location request from the clientterminal for performing privacy check on the location request prior tothe transmission of said last known location information to thecommunication terminal. The location network performs reusability checkon the stored last known location information according to the privacyprofile of the target mobile terminal or client terminal.

Identification data of the SGSN/MSCs 103, 113, 123 are maintained in theassociated HLR/HSSs 106, 116, 126. The privacy profile of UE terminal105 is stored in the GMLC of the home network, (i.e., GMLC 102).

Network Configurations

The present invention provides a number of network configurationsdepending on the location of the requesting communication terminal(client or mobile), the location of the target UE terminal 105 as wellas the location of network nodes where privacy profiles and locationreports are maintained.

First Network Configuration

The first network configuration is shown in FIGS. 2A and 2B. The clientterminal 101 is the requesting terminal, and the target UE 105 iscurrently establishing its link to home network A.

In FIG. 2A, the privacy profile and location information of the targetUE are maintained in the home GMLC 102. The client terminal 101 includesa transmit means 1011 for transmitting a location request to the homeGMLC 102 and a receive means 1012 for receiving location informationfrom the GMLC 102. GMLC 102 includes a memory 1021 for storing theprivacy profile and last known location information of UE 105, and aclient/privacy check means 1022. In response to the location requestfrom the client terminal 101, the client/privacy check means 1022performs a client check on the requesting terminal.

If the client terminal fails to pass the client check, theclient/privacy check means 1022 formulates an error message and sends itfrom a report transmit means 1026 to the requesting terminal 101. If theclient terminal is verified, the client/privacy check means 1022proceeds to reference the privacy profile of the target UE stored in thememory 1021 and performs a first privacy check on the location request.If the location request fails to pass the first privacy check, an errormessage is supplied from the check means 1022 to the report transmitmeans 1026 and transmitted to the client terminal. If the locationrequest is verified by the first privacy check, the check means 1022determines which type of location information the request specifies.

If the location request specifies type C or C/L, the client/privacycheck means 1022 instructs a notification/verification means 1024 totransmit a location request to the SGSN/MSC 103 to perform a locationestimation process with the RAN 104 to determine the location of thetarget UE 105. A location report is then returned from the SGSN/MSC 103to a second privacy check means 1025. In response to the locationreport, the second privacy check means 1025 proceeds to perform a secondprivacy check.

If the location request specifies type L or L/C, the client/privacycheck means 1022 instructs a reusability check means 1023 to make asearch through the memory 1021 for last known location information thatmeets the “age and place” requirements of the client's request. If therequested last known location information of the target UE is not storedin the memory 1021, the reusability check means 1023 generates an errormessage and transmits it to the client terminal 101 from the reporttransmit means 1026.

If the requested last known location information is stored in the memory1021, the reusability check means 1023 instructs thenotification/verification means 1024 to check the UE's privacy profileto see if notification/verification process must be performed. If thisis the case, the notification/verification means 1024 acquires theidentity of this SGSN/MSC 103 from the home HLR/HSS 106 of the target UE105 and transmits a notification/verification message to SGSN/MSC 103 torequest it to send a notification to the UE 105 for indicating that alocation request is being terminated or a verification message to it torequest it to verify the client terminal. In the former case, theSGSN/MSC 103 proceeds to request the second privacy check means toperform a second privacy check on the last known location information.In the latter case, the target UE returns a verification report to theSGSN/MSC 103, which repeats the report to the second privacy check means1025 to perform a second privacy check if the location request isverified by the target UE.

The second privacy check involves verifying the location request againstthe privacy profile of the target UE stored in the memory 1021 anddetermining whether the current or UE's last known location informationcan be sent to the client terminal. If the location request is notverified by the second privacy check, an error message is sent from thereport transmit means 1026 to the client terminal. If the locationrequest is verified by the second privacy check, the report transmitmeans 1026 transmits the location information contained in the locationreport from the SGSN/MSC 103 or a copy of the UE's last known locationinformation stored in the memory 1021.

In a MO-LR mode of operation, the mobile UE terminal 105 includes acontrol unit 1051 for transmitting a location request via a wirelessinterface 1053 to the RAN 104 for requesting the location information ofits own terminal from the SGSN/MSC 103. The location request is of thesame format as used in transmitting a location request from the clientterminal. SGSN/MSC 103 formulates and transmits a location reportcontaining current or last known location information of the UEterminal, depending on the type of location information specified by thelocation request message. The location report is transferred via the RAN104 to the UE terminal 105 and received and stored in a memory 1052 andthen displayed.

In FIG. 2B, the privacy profile and location information of the targetUE are maintained in the SGSN/MSC 103. GMLC 102 includes a client checkmeans 1027 and a report transmit means 1026. Client check means 1027performs a client check on the location request from the client terminal101. If the client check means 1027 does not verify the client terminal101, it sends an error message to the client terminal from the reporttransmit means 1026. Otherwise, the client check means 1027 acquires theidentity of SGSN/MSC 103 from HLR/HSS 106 and sends a privacy checkrequest to the SGSN/MSC 103.

SGSN/MSC 103 includes a first privacy check means 1032, which receivesthe privacy check request and performs a first privacy check using theprivacy profile of the target UE stored in a memory 1031. If thelocation request is verified, the first privacy check means 1032determines which of the location information type the verified requestspecifies.

If the location request specifies type C or C/L, the first client checkmeans 1032 instructs a notification/verification means 1034 to transmita location request to the RAN 104 to perform a location estimationprocess to determine the location of the target UE 105. A locationreport is then returned from the RAN 104 to a second privacy check means1035. In response to the location report, the second privacy check means1035 proceeds to perform a second privacy check.

If the location request specifies type L or L/C, the first privacy checkmeans 1032 instructs a reusability check means 1033 to make a searchthrough the memory 1031 for last known location information that meetsthe “age and place” requirements of the client's request. If therequested last known location information of the target UE is not storedin the memory 1031, the reusability check means 1033 generates an errormessage and transmits it from the report transmit means 1036 to theclient terminal 101. If the requested last known location information isstored in the memory 1031, the reusability check means 1033 instructsthe notification/verification means 1034 to check the UE's privacyprofile to see if notification/verification process must be performed.If this is the case, the notification/verification means 1034 transmitsa notification to the UE 105 from the RAN 104 for indicating that alocation request is being terminated or a verification message torequest it to verify the client terminal. In the former case, thenotification/verification means 1034 instructs the second privacy checkmeans 1035 to perform a second privacy check on the last known locationinformation. In the latter case, the second privacy check means 1035receives a verification report from the target UE and proceeds toperform a second privacy check if the client terminal is verified by thetarget UE.

The second privacy check involves verifying the location request againstthe privacy profile of the target UE stored in the memory 1031 anddetermining whether the current or UE's last known location informationcan be sent to the client terminal. If the location request is verifiedby the second privacy check, the report transmit means 1036 transmits tothe GMLC 102 the location information contained in the location reportfrom the RAN 104 or a copy of the UE's last known location informationstored in the memory 1031.

Second Network Configuration

According to the second network configuration shown in FIG. 3, theclient terminal 111 is the requesting terminal and the target UEterminal 105 is currently establishing its link to the home network A.The privacy profile and location report of the target UE terminal 105are maintained in the home GMLC 102 similar to that shown in FIG. 2A.

Client terminal 111 includes a transmit means 1111 for transmitting alocation request to the home GMLC 112 and a receive means 1112 forreceiving a location report from the GMLC 112. GMLC 112 includes arequest transfer means 1121 which identifies the GMLC 102 as a node thatmaintains the privacy profile and location information of the target UE105 by acquiring its node identifier from the home HLR/HSS 106 of thetarget UE. GMLC 112 includes a report transfer means 1122 for repeatinga location report from the GMLC 102 to the client terminal 111.

GMLC 102 is of identical configuration to that shown in FIG. 2A. GMLC102 operates on the location request from the GMLC 112 in a manneridentical to its operation on the location request directly receivedfrom the client terminal 101 of FIG. 2A. Therefore, the description ofGMLC 102 is omitted for simplicity.

Third Network Configuration

According to the third network configuration shown in FIG. 4, clientterminal 111 is the requesting terminal and the target UE terminal 105is currently visiting the external network C. The privacy profile andlocation report of the target UE terminal 105 are maintained in the homeGMLC 102 similar to that shown in FIG. 3.

Client terminal 111 sends a location request from transmit means 1111 tothe home GMLC 112 and receives a location report by receive means 1112from the GMLC 112. Similar to FIG. 3, the request transfer means 1121repeats the received location request to the GMLC 102 and the reporttransfer means 1122 repeats a location report from the GMLC 102 to theclient terminal 111. In the GMLC 102, memory 1021 maintains the privacyprofile and last known location information of the target UE 105. GMLC102 is of the same configuration as in FIG. 3. The operation of GMLC 102is the same as that of FIG. 3 except that its notification/verificationmeans 1024 sends notification/verification and location request messagesto the GMLC 122 of the visited network C and its second privacy checkmeans 1025 receives verification and location reports from the GMLC 122.

GMLC 122 includes a message transfer means 1221 for repeating themessage from the GMLC 102 to the SGSN/MSC 123 of the visited network Cand a report transfer means 1222 for repeating verification and locationreports from the SGSN/MSC 123 to the GMLC 102.

Fourth Network Configuration

According to the fourth network configuration shown in FIG. 5, theclient terminal 101 is the requesting terminal and the target UEterminal 105 is currently visiting the external network B. The privacyprofile and location report of the target UE 105 are maintained in thehome GMLC 102.

The location network of this configuration is similar to that of FIG. 2Awith the exception that its notification/verification means 1024 sendsnotification/verification and location request messages to the GMLC 112of the visited network B and its second privacy check means 1025receives verification and location reports from the GMLC 112.

GMLC 112 includes a message transfer means 1121 for repeating themessage from the GMLC 102 to the SGSN/MSC 113 of the visited network Band a report transfer means 1122 for repeating verification and locationreports from the SGSN/MSC 113 to the GMLC 102.

Fifth Network Configuration

According to the fifth network configuration shown in FIG. 6, the clientterminal 111 is the requesting terminal and the target UE terminal 105is currently visiting the external network B. The privacy profile andlocation report of the target UE terminal 105 are maintained in the homeGMLC 102.

The location network of this configuration is similar to that of FIG. 4with the exception that the GMLC 112 of the visited network B includes atransfer means 1123 and the notification/verification means 1024 of GMLC102 sends notification/verification and location request messages to thetransfer means 1123 for repeating it to the SGSN/MSC 113 of the visitednetwork B. The second privacy check means 1025 of GMLC 102 receivesverification and location reports from the SGSN/MSC 113 via the transfermeans 1123 of GMLC 112.

Sixth Network Configuration

The sixth network configuration is shown in FIGS. 7A and 7B in which theclient terminal 101 is the requesting terminal and the target UEterminal 105 is currently establishing its link to the home network A.In FIG. 7A, the privacy profile and location information of the targetUE terminal 105 are both maintained in the PPR 107.

In FIG. 7A, the GMLC 102 includes a client check means 1027 to perform aclient check on the location request from the client terminal 101. Ifthe request is verified, the client check means 1027 transmits anauthorization request to the PPR 107 for authorizing it to perform anumber of checks including a first privacy check, an information typecheck and a reusability test. PPR 107 includes a memory 1061 for storingprivacy profiles and location information of mobile terminals and afirst privacy check means 1072 which receives the authorization requestfrom the GMLC 102 to perform a first privacy check using the privacyprofile stored in the memory 1071. If the request is verified by thefirst privacy check, the location information type of the request isexamined.

If the client is requesting current location information, the firstprivacy check means 1072 instructs the notification/verification means1024 to determine if notification/verification is required.Notification/verification means 1024 acquires the identifier of SGSN/MSC103 from the HLR/HSS 106 and sends a location request (and anotification/verification message if required) to the identifiedSGSN/MSC to obtain location information of the target UE (with orwithout a verification report). The obtained location information issupplied to a privacy check request means 1028 of the GMLC 102. Inresponse, the privacy check request means 1028 transmits anauthorization request to a second privacy check means 1075 of the PPR toauthorize it to perform a second privacy check using the UE's privacyprofile stored in the memory 1071. If the request for the currentlocation information is verified by the second privacy check, the secondprivacy check means 1075 permits the privacy check request means 1028 ofGMLC 102 to transmit the current location information which has beenreceived from the SGSN/MSC 103 to the client terminal 101 via the reporttransmit means 1026.

If the client terminal 101 is requesting last known location informationof the target UE, the privacy check means 1072 of the PPR allows thereusability check means 1073 to perform a reusability test on the “ageand place” data of the location request to determine whether therequested last known location information is available in the memory1071. If this is the case, the reusability check means 1073 transmitsinformation to the notification/verification means 1024, indicatingwhether or not notification/verification is required. Ifnotification/verification is required, the notification/verificationmeans 1024 transmits a notification/verification message to the SGSN/MSC103. Privacy check request means 1028 responds to a verification reportfrom the SGSN/MSC 103 by checking it to see if second privacy checkshould proceed. If so, it sends an authorization request to a secondprivacy check means 1075 of PPR 107 to authorize it to perform a secondprivacy check by using the privacy profile of the target UE and returnsa privacy check report to the GMLC 102 from report transmit means 1076.If the second privacy check verifies the request, the report transmitmeans 1076 transmits a copy of the last known location information ofthe target UE from the memory 1071 to the GMLC 102, which is repeated bythe report transmit means 1026 to the client terminal 101.

If any of the results of the two privacy checks and the reusabilitycheck is unfavorable, an error report will be transmitted from thereport transmit means 1076 to the GMLC 102 and repeated by the reporttransmit means 1026 to the client terminal 101.

In FIG. 7B, the privacy profile and location report of the target UEterminal 105 are respectively maintained by the PPR 107 and the GMLC102. Client check means 1027 performs a client check on the receivedlocation request. If the request is verified, the client check means1027 transmits an authorization request to the PPR 107 to authorize itto perform a first privacy check. PPR 107 includes a privacy check means1077 which references the privacy profile of the UE terminal 105 andperforms a privacy check using the referenced privacy profile. If therequest is not verified, the privacy check means 1077 transmits an errormessage to the GMLC 102 from report transmit means 1076 to the clientterminal 101. If the request is verified, the privacy check means 1077requests the client check means 1027 of the GMLC to examine the type oflocation information of the location request.

If the client is requesting current location information, the clientcheck means 1027 of the GMLC instructs the notification/verificationmeans 1024 to acquire the identifier of the SGSN/MSC 103 from theHLR/HSS 106 and transmits a location request to the SGSN/MSC 103.Location information obtained by the SGSN/MSC 103 is transmitted to theprivacy check request means 1028. If notification/verification by the UEterminal is required, a notification/verification message is sent withthe location request and a verification report will be received by theprivacy check request means 1028. In response to the locationinformation, the privacy check request means 1028 sends an authorizationrequest to the privacy check means 1077 of the PPR to authorize it toperform a second privacy check. If the request is verified by the secondprivacy check, the privacy check means 1077 allows the privacy checkrequest means to transmit the received current location information tothe client terminal 101 via the report transmit means 1026.

If the client terminal 101 is requesting last known location informationof the target UE, the client check means 1027 of the GMLC allows thereusability check means 1023 to perform a reusability test on the “ageand place” data of the location request to determine whether therequested last known location information is available in the memory1021. If this is the case, the reusability check means 1023 instructsthe notification/verification means 1024 to check to seenotification/verification is required. If notification/verification isrequired, the notification/verification means 1024 transmits anotification/verification message to the SGSN/MSC 103 to receive averification report. Privacy check request means 1028 responds to theverification report by checking it to see if second privacy check shouldproceed. If so, it sends an authorization request to the privacy checkmeans 1077 to authorize it to perform a second privacy check by usingthe privacy profile of the target UE and returns a privacy check reportto the GMLC 102. If the request is verified by the second privacy checkmeans 1077, the report transmit means 1026 is directed to transmit acopy of the last known location information of the target UE from thememory 1021 to the GMLC 102 to the client terminal 101.

Seventh Network Configuration

The seventh network configuration is shown in FIGS. 8A and 8B in whichthe client terminal 111 is the requesting terminal and the target UEterminal 105 is currently establishing its link to the home network A.

In FIG. 8A, the privacy profile and location information of the targetUE terminal 105 are both maintained in the PPR 107. Client terminal 111includes a transmit means 1111 for transmitting a location request tothe home GMLC 112 and a receive means 1112 for receiving a locationreport from the GMLC 112. GMLC 112 includes a request transfer means1121 which identifies the GMLC 102 as a node that maintains the privacyprofile and location information of the target UE 105 by acquiring itsnode identifier from the home HLR/HSS 106 of the target UE. GMLC 112includes a report transfer means 1122 for repeating a location reportfrom the GMLC 102 to the client terminal 111.

GMLC 102 and PPR 107 are of identical configuration to that shown inFIG. 7A and hence they operate in the same manner as that of FIG. 7A onthe location request repeated by the GMLC 112.

In FIG. 8B, the privacy profile and location information of the targetUE terminal 105 are respectively maintained in the GMLC 102 and PPR 107.

Similar to FIG. 8A, the client terminal 111 transmits a location requestto the home GMLC 112 and receives a location report from the GMLC 112.GMLC 102 and PPR 107 are of identical configuration to that shown inFIG. 7B and hence they operate in the same manner as that of FIG. 7B onthe location request repeated by the GMLC 112.

Eighth Network Configuration

The eighth network configuration is shown in FIGS. 9A and 9B in whichthe client terminal 111 is the requesting terminal and the target UEterminal 105 is currently visiting the external network C.

In FIG. 9A, the privacy profile and location information of the targetUE terminal 105 are both maintained in the PPR 107. Client terminal 111transmits a location request to the home GMLC 112 and receives alocation report from the GMLC 112. GMLC 112 includes request transfermeans 1121 which identifies the GMLC 102 as a node that maintains theprivacy profile and location information of the target UE 105 byacquiring its node identifier from the home HLR/HSS 106 of the targetUE. GMLC 112 includes report transfer means 1122 for repeating alocation report from the GMLC 102 to the client terminal 111.

Since the target UE is visiting the network C, thenotification/verification means 1024 acquires the identifiers of GMLC122 and SGSN/MSC 123 from the HLR/HSS 106 when instructed from the PPR107 and sends a location request and notification/verification messageto the SGSN/MSC 123 via the message transfer means 1221 of GMLC 122 andreceives a location report and verification report via the reporttransfer means 1222 of GMLC 122.

In FIG. 9B, the privacy profile and location information of the targetUE terminal 105 are respectively maintained in the GMLC 102 and PPR 107.

The operation of FIG. 9B is similar to FIG. 8B with the exception thatlocation report and verification report are obtained from the SGSN/MSC123 via the GMLC 122.

Ninth Network Configuration

The ninth network configuration is shown in FIGS. 10A and 10B in whichthe client terminal 101 is the requesting terminal and the target UEterminal 105 is currently visiting the external network B.

In FIG. 10A, the privacy profile and location information of the targetUE terminal 105 are both maintained in the PPR 107. Client terminal 101transmits a location request to the home GMLC 102 and receives alocation report from the GMLC 102. Since the target UE is visiting thenetwork B, the notification/verification means 1024 of GMLC 102 acquiresthe identifiers of GMLC 112 and SGSN/MSC 113 from the HLR/HSS 106 wheninstructed from the PPR 107 and sends a location request andnotification/verification message to the SGSN/MSC 113 via the messagetransfer means 1123 of GMLC 112 and receives a location report andverification report via the report transfer means 1124 of GMLC 112.

In FIG. 10B, the privacy profile and location information of the targetUE terminal 105 are respectively maintained in the GMLC 102 and PPR 107.

The operation of FIG. 10B is similar to FIG. 8B with the exception thatlocation report and verification report are obtained from the SGSN/MSC113 via the GMLC 112.

Tenth Network Configuration

The ninth network configuration is shown in FIGS. 11A and 11B in whichthe client terminal 111 is the requesting terminal and the target UEterminal 105 is currently visiting the external network B.

In FIG. 11A, the privacy profile and location information of the targetUE terminal 105 are both maintained in the PPR 107. Client terminal 111transmits a location request to the home GMLC 112 which repeats therequest to the GMLC 102 after acquiring its identifier from the HLR/HSS106. Client terminal 111 receives a location report from the GMLC 102via the home GMLC 112. Since the target UE is visiting the network B,the notification/verification means 1024 of GMLC 102 acquires theidentifiers of GMLC 112 and SGSN/MSC 113 from the HLR/HSS 106 wheninstructed from the PPR 107 and sends a location request andnotification/verification message to the SGSN/MSC 113 via the messagetransfer means 1123 of GMLC 112 and receives a location report andverification report via the report transfer means 1124 of GMLC 112.

In FIG. 11B, the privacy profile and location information of the targetUE terminal 105 are respectively maintained in the GMLC 102 and PPR 107.

The operation of FIG. 11B is similar to FIG. 8B with the exception thatlocation report and verification report are obtained from the SGSN/MSC113 via the GMLC 112.

DESCRIPTION OF PREFERRED EMBODIMENTS

The MT-LR operation of a local GMLC proceeds according to flowchartsshown in FIGS. 12A to 12E if the GMLC holds the privacy information ofits home UE terminals.

In FIG. 12A, when the local GMLC receives a message from a clientterminal or from the network, the routine starts with decision step 201to examine the type and source of the message to determine whether themessage is a location request from a client terminal, a location requestrepeated from other GMLC, or the message contains an SGSN/MSC identifierfrom an HLR/HSS. If the message is a location request from clientterminal, flow proceeds to step 202 to perform a client check to verifythe requesting client terminal for agreement with the privacy profile ofthe target UE maintained in the local GMLC. If the location request isnot verified at step 202, an error message is transmitted to therequesting terminal (step 223) and the routine is terminated.

If the requesting client is verified (step 202) or the received messageis a location request from other GMLC (step 201), flow proceeds to step204 to determine whether the local GMLC is the home GMLC of the targetUE. If this is the case, flow proceeds to decision step 205 to check tosee if a PPR (Privacy Profile Register) is connected to the GMLC.

If no PPR is connected to the local GMLC, a first privacy check isperformed on the location request for agreement with the privacy profileof the target UE terminal (step 206) to determine if the locationrequest is acceptable (step 207).

The first privacy profile of a UE terminal may include grant/rejectindication of whether or not the client terminal is acceptable, orwhether or not the requested accuracy of location information isacceptable, or whether or not the requested age of last known locationinformation is acceptable. The first privacy profile may further includean indication of whether the UE terminal user is desirous ofnotification from the client terminal or verification by the UE terminalas a criteria for the acceptance of a location request. If a UE userdesires notification from the requestor, the UE user will receive anotification from the network indicating that the UE terminal is beingthe target of a location request. If a UE user desires verification, theuser will receive a verification message from the network indicatingwhether the current location request should be accepted or not. The UEterminal responds to the verification message with a verificationreport.

If first privacy check step 207 determines that the received locationrequest is not acceptable, flow proceeds to step 223 to transmit anerror message to the requesting terminal. If the location request isacceptable, flow proceeds to step 208 to perform a check on the type oflocation information contained in the received location request todetermine which of the parameters (C, L, C/L and L/C) is specified inthe request (step 209). If the type of location information specifieslast known (L) or “last known or current (L/C) location information”(indicating that the client user desires last known location informationbut satisfies with it if current location information is not available),flow proceeds to step 210 to perform a check on the last known locationinformation for reusability. If the requested “age and place”requirements of the location request meet the privacy profile of thetarget UE, a further check is made as to whether last known locationinformation that fulfills the requirements is stored in memory (step211).

If such last known location information is available, flow proceeds tostep 212 to check to see if the privacy profile of the target UEindicates that notification to or verification by the target UE isrequired. If this is the case, flow proceeds to step 213 to send anenquiry message to an HLR/HSS for requesting the identifier of aSGSN/MSC responsible for the target UE terminal. If no response isreceived from the HLR/HSS, an error message is sent to the clientterminal (step 223). When a response message is received from theHLR/HSS (step 214), the GMLC proceeds to step 215 to examine itscontents and transmits a notification/verification message to theidentified SGSN/MSC if the response message contains only SGSN/MSCidentifier. If the response message from the HLR/HSS contains theidentifier of a GMLC in addition to an SGSN/MSC identifier, the GMLCsends the notification/verification message to the identified GMLC. Ifthe privacy profile of the target UE requires only notification (step216), flow proceeds to step 218. Otherwise, flow proceeds to step 217 tocheck to see if a verification report from the UE terminal indicatesthat the requesting client terminal is verified. If the decision isnegative at step 217, flow proceeds to step 223 to send an error messageto the requesting terminal. If the decision at step 217 is affirmative,flow proceeds to step 218 to determine if the GMLC is connected to aPPR.

If no PPR is connected to the GMLC (step 218), flow proceeds to step 219to perform a second privacy check on the current or last known locationinformation to determine whether its time of location estimation and itsestimated location agree with allowed “time-zone and area” parameters ofthe UE's privacy profile (step 220). If the result of the second privacycheck is unfavorable (step 220), an error message is transmitted to theclient terminal (step 223). Otherwise, the location information isprocessed according to the UE's privacy profile if the accuracy of thelocation information is higher than the allowed accuracy (step 221). Atstep 222, the location information (current or last known) istransmitted to the client terminal. If the location information iscurrent and a copy of the current location information is stored inmemory as last known location information.

If no notification/verification is required by the UE terminal, thedecision at step 212 is negative and flow proceeds to step 219 toperform second privacy check, skipping steps 214 through 218.

If current (C or C/L) location information is specified in the receivedlocation request (step 209) or last known location information is notavailable (step 211), flow proceeds to step 231 (FIG. 12B) to transmitan enquiry message to the home HLR/HSS for requesting the identifier ofa SGSN/MSC responsible for the target UE terminal. When the requestedidentifier is received (step 232), flow proceeds to step 233 to check tosee if the privacy profile of the target UE indicates thatnotification/verification is required. If not, a location request issent to the home or external SGSN/MSC depending on the current locationof the target UE to obtain its current location information. When therequested current location information is received (step 235), flowreturns to step 218. If there is no response, an error message istransmitted to the requesting terminal (step 223). If the decision atstep 233 is affirmative, flow proceeds to step 236 to transmit alocation request and notification/verification request message to thehome or external SGSN/MSC depending on the current location of thetarget UE for receiving a response (step 237). If the current locationinformation of the target UE and a verification report is received, flowproceeds from step 237 to step 217. If no response is received, flowproceeds from step 237 to step 223 to send an error message to theclient terminal.

If the decision at step 204 indicates that the local GMLC is not thehome GMLC of the target UE, flow proceeds to step 241 (FIG. 12C) to sendan enquiry message to the external HLR/HSS, which is the home HLR/HSS ofthe external target UE, to obtain the identifier of an appropriate GMLC.When the identifier of the appropriate GMLC is obtained, a locationrequest is transmitted to the identified GMLC to obtain the locationinformation of the target UE. If the location information is receivedsuccessfully, flow proceeds to step 222 to repeat the received locationinformation to the requesting terminal. If no response is returned, anerror message is sent to the requesting terminal (step 223).

If the decision at step 201 indicates that a message such asnotification/verification message, verification report, locationrequest, or location report is received from other GMLC, flow proceedsfrom step 201 to step 251 (FIG. 12D) to repeat the received message todownstream node identified by a SGSN/MSC (or plus GMLC) identifiercontained in the message.

If a PPR is connected to the local GMLC, the decision at step 205 isaffirmative and flow proceeds to step 224 to send an authorizationrequest (for privacy check with or without a location-info-type check)to the PPR to obtain a report. The PPR performs a first privacy check onthe location request and additionally an information-type check with anattendant reusability test on stored location information of the targetUE if the PPR maintains location information of mobile terminals. Atstep 225, the GMLC receives a report from the PPR indicating a result ofthe first privacy check and a result of the reusability test. Step 225analyzes the received report. If the result of the first privacy checkis favorable and no reusability test is performed (a), flow proceeds tostep 208. Otherwise, flow proceeds to step 223 to send an error messageto the requesting terminal. If the results of the first privacy checkand reusability test are both favorable (b), flow proceeds to decisionstep 212. If the result of the first privacy check is favorable, but theresult of the reusability test is unfavorable (c), flow proceeds to step231 (FIG. 12B).

If the decision at step 218 is affirmative, flow proceeds to step 261(FIG. 12E) to send a request to the PPR for requesting it to perform asecond privacy check. At step 262, a report indicating a result of thesecond privacy check is received from the requested PPR and the resultis analyzed. If the result indicates a favorable decision, flow proceedsfrom step 262 to step 222 to transmit the location information of thetarget UE to the requesting terminal. If the report from the PPRindicates an error at step 262, flow proceeds to step 223 to send anerror message to the requesting terminal or GMLC.

If the privacy information of home UE terminals is not maintained in thelocal GMLC, the MT-LR operation of the GMLC proceeds according to theflowchart of FIG. 12F and the home SGSN/MSC of target UE terminaloperates according to the flowchart of FIG. 13.

In FIG. 12F, the routine starts with step 271 to check the type andsource of a message when it arrives on the local GMLC. If the message isa location request from a client terminal, flow proceeds to step 272 toperform a client check. If the client terminal is verified (step 273),flow proceeds to step 274 to check to see if the local GMLC is the homeGMLC of the target UE. If so, flow proceeds to step 231 (FIG. 12B).Otherwise, flow proceeds to step 241 (FIG. 12C). If the message is alocation request from other GMLC, steps 272, 273 are skipped and step274 is executed. If the message contains a node identifier, flowproceeds from step 271 to step 251 to repeat the message downstream.

The MT-LR operation of the SGSN/MSC of the present invention will bedescribed below with reference to the flowchart of FIG. 13.

The routine of a SGSN/MSC begins with the reception of a message eitherfrom a GMLC or a mobile UE terminal (step 300). If the location requestis transmitted from a GMLC and the SGSN/MSC maintains location reportsand private profiles of UE terminals (step 301), flow proceeds to step302 to perform a privacy check for agreement with the first privacyprofile of the target UE. If the request is acceptable, flow proceeds tostep 304 to check the location information type of the request. If therequest is not acceptable (step 303), an error message is returned tothe requesting GMLC (step 315).

If the location reports and private profiles of UE terminals are notmaintained by the SGSN/MSC, flow proceeds to step 331 to transmit alocation request to the RAN and repeats a location report from the RANto the requesting GMLC (step 332).

If the decision at step 300 indicates that the location request istransmitted from a UE terminal, flow proceeds to step 304, skippingsteps 302 and 303.

If the location request specifies last known location information of thetarget UE (step 304), a reusability test is provided (steps 306, 307).If the result of the reusability test at step 307 is unfavorable, flowproceeds to step 308 to transmit a location request to the associatedRAN to obtain the current location information of the target UE (steps308, 309). If no response is received, an error message is transmittedto the requesting source (step 315).

If the decision at step 307 or 309 is affirmative, flow proceeds to step310. If the location request has been received from a GMLC, flowproceeds to step 311 to perform a privacy check for agreement with asecond privacy profile of the target UE terminal (step 312). If theresult of the privacy check is unfavorable, an error message is returnedto the requesting source (step 315). Otherwise, flow advances to step313 to process the location information according to the privacy profileif the accuracy of the location information (either current or lastknown) is higher than the allowed accuracy. The processed locationinformation is then transmitted to the requesting source (step 314). Ifthe location request has been received from a UE terminal, flow proceedsfrom step 310 to step 314 to transmit the location information to therequesting UE terminal.

If the SGSN/MSC receives a notification/verification message from a GMLC(step 300), flow proceeds to step 320 to check to see if notification orverification is requested. If notification is requested, flow proceedsto step 321 to send a notification message to the target UE andterminates the routine. If verification by the target UE is requested,flow proceeds to step 322 to send a verification message to the targetUE. In response, the target UE checks the requesting terminal and sendsa verification report to the SGSN/MSC. This report is repeated by theSGSN/MSC to the requesting GMLC (step 323).

The MO-LR operation of the mobile UE terminal of the present inventionproceeds according to a flowchart shown in FIG. 14.

The routine of a mobile UE terminal starts with step 401 when the userof the UE enters a request to the terminal for requesting a locationinformation of its own terminal. The entered request data specifies oneof the types of location information as described above. At step 402,the UE terminal checks the entered type of location information anddetermines which type is specified (step 403). If the last knownlocation information is requested, flow proceeds to step 404 todetermine whether past location information is stored in the memory 1052(FIG. 2A) of the UE terminal. If the decision is affirmative at step404, flow proceeds to step 405 to check the stored last known locationinformation for reusability (step 406). If the stored informationsatisfies the privacy profile of the UE terminal, the stored locationinformation is determined to be reusable and the stored information isread (step 407) and displayed on a map (step 411). If the decision atstep 403 indicates that the entered request specifies current locationof the UE terminal or if the decision at step 404 or 406 is negative,flow proceeds to step 408 to transmit a location request to a SGSN/MSCvia a RAN. The location request is processed in the SGSN/MSC andlocation information is transmitted from the SGSN/MSC and received bythe UE terminal at step 409. Depending on the type of locationinformation specified in the transmitted location request message, thelocation information received from the SGSN/MSC is either last known orcurrent location information of the requesting UE terminal. The memoryof the UE terminal is updated with the received location information atstep 410 and the received information is displayed (step 411).

Network Modes of Operation

The present invention operates in first to tenth network modescorresponding respectively to the first to tenth network configurationsdiscussed previously. The following is a description of the networkmodes of operation using the flowcharts just described above.

First Network Mode

FIG. 15A is a sequence diagram illustrating a location network operatingin MT-LR mode in which the client terminal 101 is the requestingterminal and the mobile terminal 105 is the target UE which is currentlystaying in the home network A. The home GMLC 102 of target UE maintainsits privacy profile and location report. Client terminal 101 initiallytransmits a location request (event 501) to the home GMLC 102. Inresponse, the GMLC 102 performs a client check (event 502), a privacycheck (event 503) and a location information type check (event 504) byexecuting steps 200 through 211 of FIG. 12A. If the location requestspecifies current location information of the target UE andnotification/verification is not required, steps 231 through 235 areexecuted by sending a location request to the SGSN/MSC 103 using itsidentifier acquired from HLR/HSS 106 (events 505, 506, 507).

If the location request specifies last known location information of thetarget UE and the stored information is reusable (step 211), andnotification/verification is required (step 212), steps 213 through 215are executed by sending a notification/verification request to theSGSN/MSC 103 using its identifier obtained from HLR/HSS 106 (events 505,506, 507).

SGSN/MSC 103 executes steps 300, 320˜23 in response to thenotification/verification message (event 507) from the GMLC 102 orexecutes steps 300, 301, 331, 332 in response to the location requestfrom the GMLC 102 (event 508) and transmits a location report or averification report (event 509) to the GMLC 102. If verification reportis received, the GMLC 102 checks to see if the target UE has verifiedthe request (step 217). If the request is verified, the GMLC 102performs a second privacy check (event 510) on the current or last knownlocation information by executing steps 219 to 221 and transmitslocation information to the client terminal 101 (event 511).

FIG. 15B is a sequence diagram illustrating a location network operatingin the MT-LR mode in which the client terminal 101 is the requestingterminal, the mobile terminal 105 is the target UE establishing itswireless link to the home network A, and the home SGSN/MSC 103 of targetUE maintains its privacy profile and location report. Client terminal101 transmits a location request (event 601) to the home GMLC 102. Inresponse, the GMLC 102 executes steps 271˜273 (FIG. 12F) to perform aclient check (event 602). Being the home GMLC of the target UE, the GMLC102 makes an affirmative decision at step 274 and executes steps 231,232 (FIG. 12B) to acquire the identifier of SGSN/MSC 103 (events 603,604) from HLR/HSS 106 and sends a location request to the SGSN/MSC 103(event 605).

In response to the location request from GMLC 102, the SGSN/MSC 103executes steps 300˜307 to perform a first privacy check and informationtype check (events 606, 607) and executes steps 308, 309 to performlocation estimation process (event 608) to obtain a location report.Second privacy check is performed (event 609) by the SGSN/MSC 103 byexecuting steps 310˜313. The location report is then transmitted (step314) to the GMLC 102 (event 610), which receives this location report(step 235, FIG. 12B) and repeats it to the client terminal 101 (step222, FIG. 12A, event 611).

In FIG. 15C, the location network operates in MO-LR mode in which the UEterminal 105 transmits a location request to the SGSN/MSC 103 (event701). SGSN/MSC 103 responds to this request by executing steps 300, 304and 305 (FIG. 13) to perform an information type check (event 702). Ifthe current location is specified in the location request, the SGSN/MSC103 sends a location request to the RAN 104 (steps 308, 309, 310, 314)to provide a location estimation process (event 703). If last knownlocation is specified in the location request, the SGSN/MSC 103 performsa reusability test (steps 306, 307) and sends a location report (event704) to the UE terminal (steps 310, 314).

Second Network Mode

FIG. 16 is a sequence diagram illustrating a location network operatingin the MT-LR mode in which the client terminal 111 is the requestingterminal, the mobile terminal 105 is the target UE which is currentlystaying in its home network A, and the home GMLC 102 of target UE 105maintains its privacy profile and location report. Client terminal 111initially transmits a location request (event 801) to the home GMLC 112.In response, the GMLC 112 executes steps 201˜203 (FIG. 12A) to perform aclient check (event 802). Since the privacy information of the target UEis not available, the GMLC 112 passes through steps 204, 205 andexecutes steps 241 and 242 (FIG. 12C) to acquire the identifier of GMLC102 (events 803, 804) from the home HLR/HSS 106 of the target UE 105 andsends a location request to the GMLC 102 (event 805).

In response to the location request from GMLC 112, the GMLC 102 passesthrough steps 201, 204 and executes steps 206˜211 to perform a firstprivacy check and information type check (events 806, 807) and executessteps 212˜215 to obtain the identifier of SGSN/MSC 103 from HLR/HSS 106(events 808, 809) and transmit a notification/verification message or alocation request (event 810) to the SGSN/MSC 103. SGSN/MSC 103 performsits routine (event 811) and returns a location report or a verificationreport to the GMLC 102 (event 812). In response, the GMLC 102 executessteps 216˜218 and then performs a second privacy check on the receivedlocation information (steps 219, 220, 221, event 813). The locationreport is then transmitted (step 222, event 814) to the requesting GMLC112, which receives this location report (step 242, FIG. 12C) andrepeats it to the client terminal 111 (step 222, FIG. 12A, event 815).

Third Network Mode

FIG. 17 is a sequence diagram illustrating a location network operatingin the MT-LR mode in which the client terminal 111 is the requestingterminal, the mobile terminal 105 is the target UE which is currentlyvisiting the external network C, and the home GMLC 102 of target UE 105maintains its privacy profile and location report. Client terminal 111initially transmits a location request 901 to the home GMLC 112. Inresponse, the GMLC 112 executes steps 201˜203 (FIG. 12A) to perform aclient check 902. Since the privacy information of the target UE is notavailable, the GMLC 112 passes through steps 204, 205 and executes steps241 and 242 (FIG. 12C) to acquire the identifier of GMLC 102 (events903, 904) from the home HLR/HSS 106 of the target UE 105 and sends alocation request 905 to the GMLC 102.

In response to the location request from GMLC 112, the GMLC 102 passesthrough steps 201, 204 and executes steps 206˜211 to perform a firstprivacy check 906 and information type check 907 and executes steps212˜215 to obtain the identifiers of SGSN/MSC 123 and GMLC 122 fromHLR/HSS 106 (events 908, 909). On receiving these identifiers, the GMLC102 executes step 215 and transmits a notification/verification requestor a location request 910 to the GMLC 122. Each of these requestscontains the identifiers of SGSN/MSC 123 and GMLC 122. In response tothe request message from the GMLC 102, the GMLC 122 passes through step201 to step 251 (FIG. 12D) to repeat the received request message to theSGSN/MSC 123. SGSN/MSC 123 performs its routine 911 and returns alocation report or a verification report 912 to the GMLC 112, whichrepeats it to the GMLC 102 (step 252, FIG. 12D).

GMLC 102 executes steps 216˜218 for verification and then performs asecond privacy check 913 on the received location information (steps219, 220, 221). The location report 914 is then transmitted (step 222)to the requesting GMLC 112, which repeats this location report 915(steps 242, 222) to the client terminal 111.

Fourth Network Mode

FIG. 18 is a sequence diagram illustrating a location network operatingin the MT-LR mode in which the client terminal 101 is the requestingterminal, the mobile terminal 105 is the target UE which is currentlyvisiting the external network B, and the home GMLC 102 of target UE 105maintains its privacy profile and location report. Client terminal 101initially transmits a location request 1001 to the home GMLC 102. Inresponse, the GMLC 102 executes steps 200 through 211 (FIG. 12A) toperform a client check (event 1002), a privacy check 1003 and aninformation type check 1004. Since the target UE is visiting the networkof SGSN/MSC 113, the GMLC 102 acquires the identifiers of SGSN/MSC 113and GMLC 112 (events 1005, 1006) from HLR/HSS 106 when its has executedsteps 212 and 213, and sends a notification/verification or locationrequest message (each containing the acquired node identifiers) to theGMLC 112 (event 1007). GMLC 112 executes steps 201, 251 (FIG. 12D) torepeat the received request message to the SGSN/MSC 113.

SGSN/MSC 113 executes steps 300, 320˜323 of FIG. 13 in response to thenotification/verification message from the GMLC 112 or executes steps300, 321˜332 in response to the location request 1008 from the GMLC 112and sends a location report or a verification report 1009 to the GMLC112. GMLC 112 executes step 252 (FIG. 12D) to repeat the received reportmessage to the GMLC 102.

If verification report is received, the GMLC 102 checks to see if thetarget UE has verified the request (step 217). If the request isverified, the GMLC 102 performs a second privacy check 1010 on thecurrent or last known location information by executing steps 219 to 221and transmits location information 1011 to the client terminal 101.

Fifth Network Mode

FIG. 19 is a sequence diagram illustrating a location network operatingin the MT-LR mode in which the client terminal 111 is the requestingterminal, the mobile terminal 105 is the target UE which is currentlyvisiting the external network B, and the home GMLC 102 of target UE 105maintains its privacy profile and location report. Client terminal 111initially transmits a location request 1101 to the home GMLC 112. Inresponse, the GMLC 112 executes steps 201˜203 (FIG. 12A) to perform aclient check 1102. Since the privacy information of the target UE is notavailable, the GMLC 112 passes through steps 204, 205 and executes steps241 and 242 (FIG. 12C) to acquire the identifier of GMLC 102 (events1103, 1104) from the home HLR/HSS 106 of the target UE 105 and sends alocation request 1105 to the GMLC 102.

In response to the location request from GMLC 112, the GMLC 102 passesthrough steps 201, 204 and executes steps 206˜211 to perform a firstprivacy check 1106 and information type check 1107 and executes steps212·215 to obtain the identifiers of SGSN/MSC 113 and GMLC 112 fromHLR/HSS 106 (events 1108, 1109). On receiving these identifiers, theGMLC 102 executes step 215 and transmits a notification/verificationrequest or a location request 1110 to the GMLC 112. Each of theserequests contains the identifiers of SGSN/MSC 113 and GMLC 112. Inresponse to the request message from the GMLC 102, the GMLC 112 passesthrough step 201 to step 251 (FIG. 12D) to repeat the received requestmessage to the SGSN/MSC 113. SGSN/MSC 113 performsnotification/verification or location estimation routine 1111 andreturns a location report or a verification report 1112 to the GMLC 112,which repeats the report to the GMLC 102 (step 252, FIG. 12D).

GMLC 102 executes steps 216˜218 for verification and then performs asecond privacy check 1113 on the received location information (steps219, 220, 221). If the privacy check result is favorable, the locationreport 1114 is transmitted from the GMLC 102 (step 222) to therequesting GMLC 112, which repeats this location report 1115 to theclient terminal 111 (steps 242, 222).

Sixth Network Mode

FIG. 20 is a sequence diagram illustrating a location network operatingin the MT-LR mode in which the client terminal 101 is the requestingterminal and the mobile terminal 105 is the target UE which is stayingin the home network A. The PPR 107 is connected to the GMLC 102. Theprivacy profile and location report of target UE 105 are maintained inthe PPR 107. Client terminal 101 initially transmits a location request1201 to the home GMLC 102. In response, the GMLC 102 performs a clientcheck 1202 (steps 202˜203) and sends an authorization request 1203 tothe PPR 107 (steps 204, 224). PPR 107 performs a first privacy check1204 and a location information type check 1205 and returns a reportmessage 1206. Alternatively, information type check 1207 may be providedby the GMLC 102.

GMLC 102 analyzes the received report message 1206 (step 225) andexecutes steps 212 and 213 to send an enquiry message 1208 to HLR/HSS106 to acquire the identifier 1209 of SGSN/MSC 103 and transmits anotification/verification message or a location request message 1210 tothe SGSN/MSC 103.

SGSN/MSC 103 performs a notification/verification process or locationestimation process 1211 and returns a location report or verificationreport message 1212 to the GMLC 102.

In response to the report message, the GMLC 102 sends an authorizationrequest 1213 to the PPR 107 (steps 216, 217, 218, 261) to authorize itto perform a second privacy check 1214 and then analyzes a privacy checkreport 1215 from the PPR 107, indicating a result of the second privacycheck (step 262). If the result of the privacy check is favorable, theGMLC 102 repeats the location information 1216 received from theSGSN/MSC 103 to the client terminal 101.

Seventh Network Mode

FIG. 21 is a sequence diagram illustrating a location network operatingin MT-LR mode in which the client terminal 111 is the requestingterminal and the mobile terminal 105 is the target UE which is locatedin the home network A. The privacy profile and location report of targetUE 105 are maintained in the PPR 107 connected to the GMLC 102. Clientterminal 111 initially transmits a location request 1301 to the homeGMLC 112. In response, the GMLC 112 performs a client check 1302 (steps202˜203) and transmits an enquiry message 1303 to the HLR/HSS 106 toacquire the identifier 1304 of the home GMLC 102 of the target UE. Usingthe acquired identifier, the GMLC 112 sends a location request 1305 tothe GMLC 102. GMLC 102 responds to the location request by transmittingan authorization request 1306 to the PPR 107. PPR 107 performs a firstprivacy check 1307 and an information type check 1308 and returns areport message 1309 to the GMLC 102.

GMLC 102 analyzes the received report (step 225) and executes steps 212and 213 to acquire the identifier of SGSN/MSC 103 from HLR/HSS 106(events 1310, 1311) and transmits a notification/verification message ora location request message 1312 to the SGSN/MSC 103.

SGSN/MSC 103 performs a notification/verification process or locationestimation process 1313 and returns a location report or verificationreport message 1314 to the GMLC 102.

In response to the report message 1314, the GMLC 102 sends anauthorization request 1315 to the PPR 107 (steps 216, 217, 218, 261) toauthorize it to perform a second privacy check 1316 and analyzes aprivacy check report 1317 from the PPR 107 (step 262). If the result ofthe privacy check is favorable, the GMLC 102 sends the locationinformation 1319 received from the SGSN/MSC 103 to the client terminal101.

Eighth Network Mode

FIG. 22 is a sequence diagram illustrating a location network operatingin the MT-LR mode in which the client terminal 111 is the requestingterminal and the mobile terminal 105 is the target UE which is visitingthe external network C. The privacy profile and location report oftarget UE 105 are maintained in the PPR 107 connected to the GMLC 102.Client terminal 111 transmits a location request 1401 to the home GMLC112. In response, the GMLC 112 performs a client check 1402 andtransmits an enquiry message 1403 to the HLR/HSS 106 to acquire theidentifier 1404 of the home GMLC 102 of the target UE. Using theacquired identifier, the GMLC 112 sends a location request 1405 to theGMLC 102. GMLC 102 responds to the location request by transmitting anauthorization request 1406 to the PPR 107. PPR 107 performs a firstprivacy check 1407 and an information type check 1408 and returns areport message 1409 to the GMLC 102.

GMLC 102 acquires the identifiers of SGSN/MSC 123 and GMLC 122 fromHLR/HSS 106 (events 1410, 1411) and transmits anotification/verification message or a location request message 1412 tothe SGSN/MSC 123 via the GMLC 122.

SGSN/MSC 123 performs a notification/verification process or locationestimation process 1413 and returns a location report or verificationreport message 1414 to the GMLC 102 via the GMLC 122. In response to thereport message 1414, the GMLC 102 sends an authorization request 1415 tothe PPR 107 to authorize it to perform a second privacy check 1416 andanalyzes a privacy check report 1417 from the PPR 107. If the result ofthe privacy check is favorable, the GMLC 102 sends the locationinformation 1418 received from the SGSN/MSC 123 to the GMLC 112, whichsends location information 1419 to the client terminal 111.

Ninth Network Mode

FIG. 23 is a sequence diagram illustrating a location network operatingin the MT-LR mode in which the client terminal 101 is the requestingterminal and the target UE 105 is visiting the external network B. Theprivacy profile and location report of the target UE are maintained inthe PPR 107 connected to the GMLC 102. Client terminal 101 transmits alocation request 1501 to the home GMLC 102. In response, the GMLC 102performs a client check 1502 and transmits an authorization request 1503to the PPR 107. PPR 107 performs a first privacy check 1504 and aninformation type check 1505 and returns a report message 1506 to theGMLC 102.

GMLC 102 acquires the identifiers of SGSN/MSC 113 and GMLC 112 fromHLR/HSS 106 (events 1507, 1508) and transmits anotification/verification message or a location request message 1509 tothe SGSN/MSC 113 via the GMLC 112.

SGSN/MSC 113 performs a notification/verification process or locationestimation process 1510 and returns a location report or verificationreport message 1511 to the GMLC 102 via the GMLC 112. In response to thereport message 1511, the GMLC 102 sends an authorization request 1512 tothe PPR 107 to authorize it to perform a second privacy check 1513 andanalyzes a privacy check report 1514 from the PPR 107. If the result ofthe privacy check is favorable, the GMLC 102 sends location information1515 received from the SGSN/MSC 113 to the client terminal 101.

Tenth Network Mode

FIG. 24 is a sequence diagram illustrating a location network operatingin MT-LR mode in which the client terminal 111 is the requestingterminal and the target UE 105 is visiting the external network B. Theprivacy profile and location report of target UE 105 are maintained inthe PPR 107 connected to the GMLC 102. Client terminal 111 transmits alocation request 1601 to the home GMLC 112. In response, the GMLC 112performs a client check 1602 and transmits an enquiry message 1603 tothe HLR/HSS 106 to acquire the identifier 1604 of the home GMLC 102 ofthe target UE. Using the acquired identifier, the GMLC 112 sends alocation request 1605 to the GMLC 102. GMLC 102 responds to the locationrequest by transmitting an authorization request 1606 to the PPR 107.PPR 107 performs a first privacy check 1607 and an information typecheck 1608 and returns a report message 1609 to the GMLC 102.

GMLC 102 acquires the identifiers of SGSN/MSC 113 and GMLC 112 fromHLR/HSS 106 (events 1610, 1611) and transmits anotification/verification message or a location request message 1612 tothe SGSN/MSC 113 via the GMLC 112.

SGSN/MSC 113 performs a notification/verification process or locationestimation process 1613 and returns a location report or verificationreport message 1614 to the GMLC 102 via the GMLC 112.

In response to the report message 1614, the GMLC 102 sends anauthorization request 1615 to the PPR 107 to authorize it to perform asecond privacy check 1616 and analyzes a privacy check report 1617 fromthe PPR 107. If the result of the privacy check is favorable, the GMLC102 sends the location report 1618 received from the SGSN/MSC 113 to theGMLC 112 which transmits the location information 1619 to the clientterminal 111.

1. A location service system for locating a target mobile terminal,comprising: a client terminal which transmits a location request of thetarget mobile terminal, and requested accuracy and requested allowableage; a positioning system which produces location information of thetarget mobile terminal; and a gateway which transmits the locationrequest to said positioning system and stores previously obtainedlocation information of the target mobile terminal and a privacy profileof the target mobile terminal, wherein the gateway performs a firstprivacy check for verifying the location request by referring to theprivacy profile of the target mobile terminal, performs a reusabilitycheck to determine if the stored, previously obtained, locationinformation satisfies the requested accuracy and the requested allowableage, and if the reusability check is affirmative, then performs a secondprivacy check on the stored, previously obtained, location informationby referring to information specified in the location request based onthe privacy profile of the target mobile terminal, without transmittingthe verified location request to the positioning system, in order todecide whether said gateway can transmit the stored, previouslyobtained, location information to the client terminal.
 2. The locationservice system of claim 1, wherein said gateway transmits a notificationmessage to said target mobile terminal if the privacy profile of thetarget mobile terminal indicates that the notification message is to besent to said target mobile terminal in the first privacy check.
 3. Thelocation service system of claim 2, wherein said notification messageincludes a verification request and said gateway receives a verificationreport from the target mobile terminal to determine if the verificationreport allows said stored, previously obtained, location information tobe forwarded to said client terminal.
 4. A location method of a locationservice system for locating a target mobile terminal, wherein apositioning system for producing location information of the targetmobile terminal in response to a request from a gateway is provided, themethod comprising: transmitting, at a client terminal, a locationrequest of the target mobile terminal, requested accuracy and requestedallowable age; performing, at the gateway which stores previouslyobtained location information of the target mobile terminal and aprivacy profile of the target mobile terminal, a first privacy check forverifying the location request from the client terminal by referring tothe privacy profile of the target mobile terminal; performing, at thegateway, a reusability check to determine if the stored, previouslyobtained, location information satisfies the requested accuracy and therequested allowable age; and performing, at the gateway, a secondprivacy check on said stored, previously obtained, location informationby referring to information specified in the verified location requestin order to decide whether the gateway can transmit the stored,previously obtained, location information to the client terminal withouttransmitting the verified location request to the positioning system ifsaid reusability check is affirmative.
 5. The method of claim 4, whereinthe performing of the second privacy check comprises the step oftransmitting a notification message to said target mobile terminal ifthe privacy profile of the target mobile terminal indicates that thenotification message is to be sent to the target mobile terminal in thefirst privacy check.
 6. The method of claim 5, wherein the step oftransmitting the notification message to said target mobile terminalincludes: transmitting a verification message to said target mobileterminal; receiving a verification report from the target mobileterminal; and determining if the verification report allows said stored,previously obtained, location information to be forwarded to said clientterminal.
 7. A gateway of a location service system, wherein apositioning system for producing location information of a target mobileterminal is provided for locating the target mobile terminal, thegateway comprising: storage means for storing previously obtainedlocation information of the target mobile terminal from the positioningsystem and a privacy profile of the target mobile terminal; firstprivacy check means for verifying a location request of the targetmobile terminal, requested accuracy, and requested allowable age from aclient terminal by referring to the privacy profile of the target mobileterminal stored in the storage means; reusability check means fordetermining if the stored, previously obtained, location informationstored in the storage means satisfies the requested accuracy and therequested allowable age; and second privacy check means for performing asecond privacy check, if the reusability check is affirmative, on saidstored, previously obtained, location information stored in the storagemeans, without transmitting the verified location request to thepositioning system, in order to decide whether the stored, previouslyobtained, location information stored in the storage means can betransmitted to the client terminal.
 8. The gateway of claim 7, whereinsaid gateway further comprises notification means for transmitting anotification message to said target mobile terminal if the first privacycheck means has detected, in the privacy profile of the target mobileterminal, that the notification message is to be transmitted to thetarget mobile terminal.
 9. The gateway of claim 8, wherein saidnotification message includes a verification request, and saidnotification means receives a verification report from the target mobileterminal and determines if the verification report allows the stored,previously obtained, location information to be forwarded to the clientterminal.
 10. A gateway of a location service system, wherein apositioning system for producing location information of a target mobileterminal is provided for locating the target mobile terminal, thegateway comprising: a storage unit that stores previously obtainedlocation information of the target mobile terminal from the positioningsystem and a privacy profile of the target mobile terminal; a firstprivacy check unit that verifies a location request of the target mobileterminal, requested accuracy, and requested allowable age from a clientterminal by referring to the privacy profile of the target mobileterminal stored in the storage unit; a reusability check unit thatdetermines if the stored, previously obtained, location informationstored in the storage means satisfies the requested accuracy and therequested allowable age; and a second privacy check unit that performs asecond privacy check, if the reusability check is affirmative, on saidstored, previously obtained, location information stored in the storageunit, without transmitting the verified location request to thepositioning system, in order to decide whether the stored, previouslyobtained, location information stored in the storage unit can betransmitted to the client terminal.